Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations present, the description carries the full burden and does so richly: managed DNS hosting after completion, custom nameservers rejected, OTP emailed to the current owner and never exposed in output or logs, and the lockout rule (attempts consumed, code locked after 5 failures). These are exactly the operational facts an agent cannot get from the schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Four sentences, each carrying a distinct fact: purpose, hosting consequence, OTP retrieval path, and failure/completion semantics. Front-loaded with the action and the required input, with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a two-parameter tool with no annotations and no output schema, the description supplies the prerequisites, the side effects, the security-relevant OTP handling, the retry/lockout behavior, and the terminal step. An agent has everything needed to invoke it correctly and warn the user.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters (fqdn, code) are already documented with format hints in the schema, setting the baseline at 3. The description reinforces that 'code' comes from the current owner but adds no syntax or format detail beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Request the transfer of a domain to the caller') and immediately scopes it with the required input ('using a transfer code obtained from its current owner'). This clearly distinguishes it from siblings domain_transfer_create_code (generates a code) and domain_transfer_confirm (finishes the transfer).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Names the prerequisite (transfer code from the current owner) and the follow-up tool ('the transfer completes only via domain_transfer_confirm'), which routes the agent correctly. It does not explicitly contrast with domain_register for non-transfer acquisitions, so it stops short of full when/when-not guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.